Abstract: "Tandem solar cells, in which two solar cells
with different absorption characteristics are linked to use a wider range
of the solar spectrum, were fabricated with each layer processed from
solution with the use of bulk heterojunction materials comprising
semiconducting polymers and fullerene derivatives. A transparent titanium
oxide (TiOx) layer separates and connects the front cell and the back cell.
The TiOx layer serves as an electron transport and collecting layer for the
first cell and as a stable foundation that enables the fabrication of the
second cell to complete the tandem cell architecture. We use an inverted
structure with the low band-gap polymer-fullerene composite as the
charge-separating layer in the front cell and the high band-gap polymer
composite as that in the back cell. Power-conversion efficiencies of more
than 6% were achieved at illuminations of 200 milliwatts per square
centimeter."

This 2007 report from Science was cited 42
times in current journal articles indexed by Clarivate Analytics
during January-February 2009. During that two-month period, only two other
papers designated under the main heading of physics and published in the
last two years, aside from reviews, garnered higher citation totals. (This
cross-disciplinary materials-science paper, it should be noted, would also
be suitable for the main Hot Papers "chemistry" category.) Prior to the
most recent bimonthly count, citations to the paper have accrued as
follows:

SOURCE:
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